<?php
/*
	+-----------------------------------------------------------------------------+
	| ILIAS open source                                                           |
	+-----------------------------------------------------------------------------+
	| Copyright (c) 1998-2001 ILIAS open source, University of Cologne            |
	|                                                                             |
	| This program is free software; you can redistribute it and/or               |
	| modify it under the terms of the GNU General Public License                 |
	| as published by the Free Software Foundation; either version 2              |
	| of the License, or (at your option) any later version.                      |
	|                                                                             |
	| This program is distributed in the hope that it will be useful,             |
	| but WITHOUT ANY WARRANTY; without even the implied warranty of              |
	| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               |
	| GNU General Public License for more details.                                |
	|                                                                             |
	| You should have received a copy of the GNU General Public License           |
	| along with this program; if not, write to the Free Software                 |
	| Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. |
	+-----------------------------------------------------------------------------+
*/

/**
* Class ilLearningProgress
*
* @author Stefan Meyer <smeyer@databay.de>
*
* @version $Id: class.ilLearningProgress.php 17707 2008-10-16 16:16:36Z smeyer $
*
* @extends ilObjectGUI
* @package ilias-core
*
*/

class ilLearningProgress
{
	var $db = null;

	function ilLearningProgress()
	{
		global $ilDB;
		
		$this->db = $ilDB;
	}

	// Static
	function _tracProgress($a_user_id,$a_obj_id, $a_obj_type = '')
	{
		global $ilDB;

		require_once 'Services/Tracking/classes/class.ilChangeEvent.php';
		ilChangeEvent::_recordReadEvent($a_obj_id, $a_user_id);
		return true;
	}

	function _getProgress($a_user_id,$a_obj_id)
	{
		require_once 'Services/Tracking/classes/class.ilChangeEvent.php';
		$events = ilChangeEvent::_lookupReadEvents($a_obj_id, $a_user_id);

		foreach($events as $row)
		{
			if ($progress)
			{
				$progress['spent_seconds'] += $row['spent_seconds'];
				$progress['access_time'] = max($progress['access_time'], $row['last_access']);
			}
			else
			{
				$progress['obj_id'] = $row['obj_id'];
				$progress['user_id'] = $row['usr_id'];
				$progress['spent_seconds'] = $row['spent_seconds'];
				$progress['access_time'] = $row['last_access'];
				$progress['visits'] = $row['read_count'];
			}
		}
		return $progress ? $progress : array();
	}
	
	/**
	 * lookup progress for a specific object
	 *
	 * @access public
	 * @param int obj_id
	 * @return array of progress data 
	 */
	public static function _lookupProgressByObjId($a_obj_id)
	{
		include_once('./Services/Tracking/classes/class.ilChangeEvent.php');
		foreach(ilChangeEvent::_lookupReadEvents($a_obj_id) as $row)
		{
			if(isset($progress[$row['usr_id']]))
			{
				$progress[$row['usr_id']]['spent_seconds'] += $row['spent_seconds'];
				$progress[$row['usr_id']]['read_count'] += $row['read_count'];
				$progress[$row['usr_id']]['ts'] = max($row['last_access'],$progress[$row['usr_id']]['ts']);
			}
			else
			{
				$progress[$row['usr_id']]['spent_seconds'] = $row['spent_seconds'];
				$progress[$row['usr_id']]['read_count'] = $row['read_count'];
				$progress[$row['usr_id']]['ts'] = $row['last_access'];
				
			}
			$progress[$row['usr_id']]['usr_id'] = $row['usr_id'];
			$progress[$row['usr_id']]['obj_id'] = $row['obj_id'];
		}
		return $progress ? $progress : array();
	}

	function _updateProgress($data)
	{
		require_once 'Services/Tracking/classes/class.ilChangeEvent.php';
		ilChangeEvent::_recordReadEvent($data['obj_id'], $data['usr_id']);
	}
}
?>